Chuck assembly for rock drills



Parme-d Feb. 4e, .19.26.

` UNITED sTATiazsA ori-"ics,`

HARRY V. HAIGHT, or SHERBROOKE, QUEBEC, CANADA, AssIGNoR To IiveRsoL.` EAND COMPANY, or. JERSEY CITY, NEW JERSEY, A oonPoEA'rIoN oF NEW JERSEY.

CHUCK ASSEMBLY IOR ROCK lDRILLS.

Application led January 22, 1925. Serial No. 3,905.

Be it known that I, HARRY V. HAIGi-Ir, a citizen fof the Dominion of Canada, and a resident of Sherbrooke, Province of Quebec, Canada, have invented a certain Chuck Assembly for Rock Drills, of which the following is a specification accompanied by drawings. i

This invention relates to vrock drills and more particularly lto chuck assemblies for transmitting rotation to the drill steel.

One object of the inventionfis to enable the driver or element whichengages thev made separate lugs of the drill steel to bev from the chuck or chuck key. Another ob'- ject is to enable the drive-r to be reversed so as to present fresh wearing surfaces to the drill steel lugs. These objects are ac eomplished by constructing the driver sepa rately from the chuck and chuck key and providing chuck jaws to .engage the latter parts. Preferably, the chuck jaws are similar at the opposite ends so-that the driver as it becomes worn on one surface may be reversed so as to present perfect faces to the lugs of the drill steel.. Constructed in this manner, the driver may be formed from bar stock instead of being forged, and in addition is a cheaper renewable part partly because it is made Iof less material and partly because it can be used longer, being usable on bith surfaces duc to its reversible feature.

The invention will be more clearly understood by reference to the drawings which illustrate a preferred embodiment which the 4invention may assume vin practice.

In the drawing in which similar reference characters refer to similar parts,

Figure l is-a longitudinal view in section of the front cud of a rock drillV showing the fronthead and chuck assembly tlicrewi thin g.

Figure 2 is a perspective view' of the driver;

Figure 3 is a perspective view -of the front cud of the chuck, showing more particularl) the manner in which the `chuck is engaged by the driver; and

Figure 1 is a perspective view of the chuck key for preventing the drill steel from diseiigaging the chuck. X

Referring to the drawings, the forward part onl7 of a rock drill is shown which iri- .blows therefrom.

- `to this end there are cludes the cylinderi/kto which is attached,

in any suitable manner, the'frontv-.head'B having an inwardly extendingflahe C to retain the chuck assembly.' The orwardend of the cylinder is sealed by means of a flanged front, cylinder head. D through which the luted nose E of i ton is adapted to reci recate. The chuck. as-

f the hammer pis* sembly comprises a c uck F having a chuck: f

nut G to cooperate wit-h the iuted nose E ofthe piston, a `chuck key H which is adapted to retain the lug steel J within the chuck, and a ldriver K is interposed between the chuck F and the chuck key The vshank of the drill steel ,J isarranged to eX- tend into the chuck F and into the path of the reciprocatin O b llie chuck lbushingL is provided to guide the shanlc ofthe drill steel' J. and to prevent thesteel from extending beyond a predetermined' point into The chuck bushing Lfis' there the chuck. fore `press fitted into' thechuck- F fand lis seated against a shoulderfO formed on the interior surface "of the chuck. The `lugs l, being largerthan the internal bore'- of the bushing L, prevent 'the steelv from extending too far into the chuck F.

The chuck key H is provided with grooves or ways Q to permit lthe lugs Pv to pass through the key H, but, owing to theirnarrow width, normally prevent the steel from being pulled out except whenthe lugsy P register` with these grooves.

It is desirable to maintain simultaneous rotation 'of the chuck F, the driver K and the chck key H and therefore chuck jaws R 2111 chuck key H respectively'to engage with lonpiston, E .toreceive the S are providedon the chuck F` and the I gitudinally extending teeth' or 'jaws' T on the driver K. The driver- K vis provided with means to engage the lugs P of the steelJ and formed L vlongitudinal ribs U internally on the driver'K. The ribs U are subjected to grinding and wear fromV the lugs P and wear out-relatively soon' as compared with the other parts of the chuck assembly. For thisreasonf the driver K is made separat-e from the chuck F andthe chuck key H. It may thusbe replaced with- I out the necessityof. replacing the other parts "of the chuck assembly. y Invaddition to 'thisI feature the driver K is made reversibleand to this end- .tlie teeth or jaws T are similar on the opposite ends of the driver K. The driver K can thus be 'turned to present a fresh surface for wear on the other side.

In order that the driver K may be made 5 of the least material, the ribs U are arranged to extend. in line with the teeth or jaws T v and therefore are longer than the main body of the driver K. The greatest possible le O'th of the ribs U is thus provided. Norlorma ly, only one surface of the ribs U is worn since there is ordinarily some space left within the driver K to permit thestecl J to move longitudinally, therefore, ,when the driver K constructed las above described is operating clutch members totransmit rotation from the chuck to the drivcrand chuck kcv.

2. A chuck assembly for a rook drill comprising a chuck having clutch members, a chuck bushing within the chuck to receive the shank of a drill steel, a chuck key hav- T 4ing grooves to permit lugs on the drill steel to enter and also having clutch members, a reversible ldriver interposed between the chuck and chuck keyhaving similar clutch membeis similarly placed at its ends to engage the clutch members of the chuck key and chuck, and longitudinal ribs within the 20 the clutch jIaws or teeth T are strengthened 15 reversed, the worn ends of the-ribs U are placed at the, front end where they will no longer receive wear and the unworn surfaces then are placedfin position to engaoe the lugs P. Due to this arrangement of the ribs U,

materially and breakage is prevented.

I claim 1. A chuck assembly for a rock drill comprising a chuck, a chuck bushing within the 25 chuck to receive the shank of la drill steel, a

ends toengage the chuck key and chuck, andl chuck key having grooves to permit lugs on the drill-steel to enter, and areversible driver interposed between the chuck and chuck key provided with means to engage 30 the lugs on the drill steel, said chuckand chuck key being provided with clutch members and the intermediate driver having covlongitudinal ribs extending the length of the driver yand the clutch members to engage the lugs of the drill steel;

In testimony whereof I have signed this specilication.

HARRY v. HAIGH'r. 

